From 9f84f2bb6621a674bab1510684f4b946da83ccb4 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Thu, 14 Apr 2005 22:35:12 +0000 Subject: [PATCH] Make equalTupleDescs() compare attlen/attbyval/attalign rather than assuming comparison of atttypid is sufficient. In a dropped column atttypid will be 0, and we'd better check the physical-storage data to make sure the tupdescs are physically compatible. I do not believe there is a real risk before 8.0, since before that we only used this routine to compare successive states of the tupdesc for a particular relation. But 8.0's typcache.c might be comparing arbitrary tupdescs so we'd better play it safer. --- src/backend/access/common/tupdesc.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/src/backend/access/common/tupdesc.c b/src/backend/access/common/tupdesc.c index d7bf7cffce..ad5b5b1339 100644 --- a/src/backend/access/common/tupdesc.c +++ b/src/backend/access/common/tupdesc.c @@ -274,10 +274,15 @@ equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2) /* * We do not need to check every single field here: we can - * disregard attrelid, attnum (it was used to place the row in the - * attrs array) and everything derived from the column datatype. - * Also, attcacheoff must NOT be checked since it's possibly not - * set in both copies. + * disregard attrelid and attnum (which were used to place the row + * in the attrs array in the first place). It might look like we + * could dispense with checking attlen/attbyval/attalign, since these + * are derived from atttypid; but in the case of dropped columns + * we must check them (since atttypid will be zero for all dropped + * columns) and in general it seems safer to check them always. + * + * attcacheoff must NOT be checked since it's possibly not set + * in both copies. */ if (strcmp(NameStr(attr1->attname), NameStr(attr2->attname)) != 0) return false; @@ -285,12 +290,18 @@ equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2) return false; if (attr1->attstattarget != attr2->attstattarget) return false; + if (attr1->attlen != attr2->attlen) + return false; if (attr1->attndims != attr2->attndims) return false; if (attr1->atttypmod != attr2->atttypmod) return false; + if (attr1->attbyval != attr2->attbyval) + return false; if (attr1->attstorage != attr2->attstorage) return false; + if (attr1->attalign != attr2->attalign) + return false; if (attr1->attnotnull != attr2->attnotnull) return false; if (attr1->atthasdef != attr2->atthasdef) -- 2.39.5